Drive for multicolor press



y 1955 c. w. HARROLD DRIVE FOR MULTICOLOR PRESS 2 Sheets-Sheet 1 FiledMay 27, 1952 m N o 0 M N INVENTOR. (l/AME: M/ahmvow 2 Sheets-Sheet 2Filed May 27, 1952 INVENTOR. 0mm. E5 M4 fin /m4 a United DREVE FORMULTICOLOR PRESS Charles W. Harroid, University Heights, Ohio, assignorto Harris-Seybold Company, Cleveland, Ohio, a corporation of DelawareApplication May 27, 1952, Serial No. 298,364

12 Claims. (Cl. rill-183) This invention relates to improvements indrives for sheet fed multicolor presses.

Customarily the different units are driven through a train of gearspowered by a single motor. A long train of gears, such as would benecessary for driving the printing units of a five color press forexample, including means for transferring sheets from each unit to thenext, is placed under heavy stress if connected at one point with asingle driving motor. The gearing itself absorbs considerable power inaddition to that required for driving the different units of themachine. Also under the pressure applied by the driving motor thedifferent gear elements tend to yield or bend slightly and in order tocounteract this tendency wider faced gears must be pro vided in thatpart of the train nearest the motor which is a disadvantage in that itinterferes with standardization of the different units of the press.

When two motors are applied at different points to a train of gearsconnecting the units of a sheet fed multicolor press, the gear train isrelieved of some of this undue stress and a more efficient driveresults. however that in such a case there may occur what may be termedfloating backlash, which is the condition that exists when anoverbalancing part of the load shifts from one motor to the other. Atsuch times the direction of the backlash changes and the feed of sheetsis so affected thereby that registration is impaired. in order toovercome this difficulty I employ two motors of like type but ofsubstantially different power output, with controls for operating themat equal speed.

One of the objects of the invention therefore is the application ofdriving force at two or more different points in a sheet fed multiunitprinting press, while preventing floating backlash, that is backlashshifting back and forth.

Another object is the provision of driving means for multiunit pressessuch that the number of units may be increased without increasing thestrength of the gears in the gear train.

Another object is the provision of a two motor drive for multiunitpresses requiring less horsepower than a drive employing a single motor.

Another object is the provision of a drive for a multiunit presscomprising two motors of the same speed but different torque applied atspaced points along a gear train connecting the units, whereby the motorwhich is more powerful in relation to the load imposed upon it controlsbacklash at all times.

Still another object is the provision of a drive for multiunit presseswhich will produce minimum deflection in the gears of the driving trainand cause a minimum of register trouble.

Other objects and features of novelty will appear as I proceed with thedescription of that embodiment of the invention which, for the purposesof the present application, I have illustrated in the accompanyingdrawings, in which:

Fig. 1 is an elevational side View, diagrammatic in l have found ratesFatent O P1 no character, of a five unit rotary offset printing pressembodying the invention;

Fig. 2 is a plan view of a portion of the press, the blanket and platecylinders being removed in order to better illustrate the invention;

Fig. 3 is a side elevational view on a larger scale of a portion of themachine illustrated in Fig. 1;

Fig. 4 is a fragmental cross sectional view taken substantially on theline 44 of Fig. 3, and

Fig. 5 is a wiring diagram of a common control for a pair of A. C.motors employed in connection with the invention.

In the drawings I have illustrated the application of the invention to asheet fed offset printing press. The diagrammatic showing of Figure 1includes a feed pile ill of sheets, feed cylinders 11 and 12, a deliverycylinder 13 and a delivery pile 14. The press itself comprises fiveprinting units A, B, C, D and E, in each unit of which there areimpression, blanket, and plate cylinders 15, 16 and 17 respectively. Allthree cylinders of each unit are of substantially the same size, as isusual, and are operatively interconnected to turn at the same surfacespeed by means of intermeshing gears 18, 19 and 26.

Between each pair of successive printing units there is a sheet transfermeans, which may conveniently consist of a transfer cylinder 21, 21a,21b or Me of twice the diameter of the impression cylinders. Eachimpression cylinder is provided with a set of sheet grippers 22 shown inFig. 2 on one unit only, and each transfer cylinder is provided with twosets of diametrically opposed sheet grippers 23, one set only of whichis shown in Fig. 2 in connection with transfer cylinder 23. It is to beunderstood that all impression cylinders and transfer cylinders aresimilarly equipped. This sheet gripper arrangement and means foroperating grippers being well known in the art, further disclosure withrespect to the same is deemed unnecessary.

As indicated in Fig. 4 of the drawing the gears 18, 19 and 29 may bemounted on their respective cylinders 15, 16 and i7 internally of themachine frame 24. Outside of one side member of the frame the shaft ofeach impression cylinder carries a gear 25. The gear 25 of each end unitmeshes with a double size gear 26 on the shaft of the transfer cylinderadjacent thereto, while the impression cylinder gear 25 of each of thethree intermediate units meshes with a double size transfer cylindergear 26 on either side thereof. In this way there is constituted a trainof gears interconnecting the various units to cause their cylinders toturn at the same surface speed. Correct angular relationship between thecylinders of the various units is thus maintained, and thissynchronizing of the units is of course essential for maintainingregister in the several color impressions made by the different units.

Power is communicated to the train of gears just referred to by twomotors 3t) and 31 of the same type but of unequal power output. Thediiference in power output should be substantial in order that there maybe no shift of drive control from one motor to the other under anyforeseeable load shifting as between printing units. 1 have found that apower output of the larger motor equal to twice that of the smallermotor is entirely effective and satisfactory, but i do not wish toconfine the invention to that ratio.

Motor 3% by means of a plurality of V-belts 32 drives a pulley 33mounted on a shaft journaled in the frame between two transfer cylinders21 and Zia. Shaft 34 carries a pinion 35 which meshes with a pinion 36on another shaft 37, this latter shaft carrying also a pinion 38 whichmeshes with gear 26 on transfer cylinder 21a.

The smaller motor 31 drives a plurality of V-belts 40 which run over apulley 41 mounted on a shaft 42 journaled in the frame between transfercylinders 21a and 21b. Through pinions 43, 44 and 45, similar in allrespects to pinions 35, 36 and 38, power from motor 31 is transmitted.to transfer cylinder 21b. The power transmitted to transfer cylinder21!) fromthe larger motor through transfer cylinder 21a and impressioncylinder 21 of the C unit is always greater by a substantial amount thanthe power transmitted to it from the smaller motor through the pinions43, 44, 45. Hence there is no tendency toward floating backlash.Consequently good printing register in all colors is maintained.

Means is provided for controlling the two motors to cause them to turnat the same speed and to maintain the ratio of their power outputsconstant. In Fig. 5 I have shown by way of example, using a conventionalsingle line diagram, two A. C. slip ring motors connected to the supplyline 5% by conductors 51 and 52. In the slip ring circuit of the largermotor 36 there is a resistor 53, while a similar type resistor 54 isincluded in the slip ring circuit of the smaller motor 31. are selectedto produce substantially the desired relationship in the power outputsof the two motors at normal speed. The slip ring circuits also containvariable resistors 55 and 56 respectively which can be adjustedmanually, as indicated by means of a handle 57, or by automatic means,to obtain different but always equal operating speeds in the two motors.Auxiliary circuits necessary for accomplishing the above functions arenot shown since their construction and use are well known.

Instead of two A. C. motors, two D. C. motors of similar characteristicsmay be employed and a common control provided for varying the speedwhile maintaining a given power output ratio. Circuits for this purposeare known in the electrical art, but as the details of the same are notper se a part of the present invention no specific disclosure is given.

The use of two or more motors permits the use of the same width of gearsthroughout the gear train of a five color press as are satisfactory fora two color and four color press, whereas a single motor of sufficienthorsepower to operate a live color press would wear out such gearsrapidly or cause breakage of the same. Driving from two motors is alsomore efiicient from the standpoint of power consumption, it having beenfound in practice that two motors require about ten percent lesshorsepower than a single motor in the operation of a five color press.

In the embodiment illustrated the more powerful motor is the one whichis applied to the train first in respect to the direction of travel ofsheets through the press. That arrangement is satisfactory and ispreferred. However, the reverse arrangement is entirely workableprovided that the ratio of power output of the first motor to the loadon its side of the gear driven by the other motor is greater than theratio of the power output of the second motor to the remaining load. Inother words the output of the first motor must be such that after it hasassumed the load to the rear of the gear driven by the second motor,there is a substantial excess of power left to be fed into the train inadvance of the gear driven by the second motor, thus preventing a shiftin backlash such as may tend to occur when the load on a unit is changedsomewhat due to different printing conditions.

Having thus described my invention, I claim:

1. In a multicolor sheet fed printing press or the like, a gear trainfor driving the press including a plurality of continuously meshedgears, two motors in driving relation with spaced apart gears of saidtrain, the ratio of power output of one of said motors to the load onits side of the gear driven by the other motor being greater than theratio of the power output of the latter motor to the remaining load,whereby backlash at all points in said gear train is maintained alwaysin the same direction.

2. In a multicolor sheet fed printing press, a series These resistors ofthree or more printing units each including an impression cylinder andassociated mechanism, sheet transfer means between the impressioncylinders of each pair of adjacent units, sheet grippers on saidimpression cylinders and on said sheet transfer means adapted to conveysheets in register through the printing units, a gear train for drivingsaid printing units and said sheet transfer means including a gear foreach of said impression cylinders and sheet transfer means, two motorsof unequal power output, each of said motors being in driving relationwith a gear on each of two sheet transfer means, the ratio of poweroutput of one of said motors to the load on its side of the gear drivenby the other motor being greater than the ratio of the power output ofthe latter motor to the remaining load, whereby backlash at all pointsin said gear train is maintained always in the same direction.

3. In a multicolor sheet fed printing press including a series of threeor more printing units each including an impression cylinder andassociated mechanism, sheet transfer means between the impressioncylinders of each pair of adjacent units, and sheet grippers on theimpression cylinders and on the sheet transfer means adapted to conveysheets in register through the printing units, a gear train for drivingthe press including a plurality of continuously meshed gears, twodriving pinions each meshing with a different gear of said gear train,two motors, one connected to the rear driving pinion and the otherconnected to the forward driving pinion considered with reference to thedirection of sheet travel, the ratio of power output to load effectiveon the train to the rear of the gear with which the forward pinionmeshes being greater than the ratio of power output to load on that gearand parts forward thereof, whereby power from the rear motor istransmitted through said gear to the forward portion of the train andwhereby backlash throughout the gear train is maintained always in thesame direction.

4. in a multicolor sheet fed printing press, a series of three or moreprinting units each including an impression cylinder and associatedmechanism, sheet transfer means between the impression cylinders of eachpair of adjacent units, sheet grippers on said impression cylinders andon said sheet transfer means adapted to convey sheets in registerthrough the printing units, a gear train for driving said printing unitsand said sheet transfer means including a gear for each of saidimpression cylinders and sheet transfer means, a driving pinion indriving relation with the gears of each of two sheet transfer means, twomotors of unequal power output, one connected to the rear driving pinionand the other connected to the forward driving pinion considered withreference to the direction of sheet travel, the ratio of power output toload effective on the train to the rear of the transfer means geardriven by the forward pinion being greater than the ratio of poweroutput to load on that transfer means gear, whereby power from the rearmotor is transmitted through said forward transfer means gear to theforward portion of the gear train, and whereby backlash throughout thegear train is maintained always in the same direction.

5. In a multicolor sheet fed printing press including a series of threeor more printing units each including an impression cylinder andassociated mechanism, sheet transfer means between the impressioncylinders of each pair of acjacent units, and sheet grippers on saidimpression cylinders and on said sheet transfer means adapted to conveysheets in register through the printing units, a gear train for drivingthe press including a plurality of gears, two motors in driving relationwith spaced apart gears of said train, the difference in power output ofsaidmotors with relation to the load borne by each of them being such asto cause power from the motor of greater output to be transmittedthrough the gear driven by the motor of smaller output, whereby backlashat all points in said gear train is maintained always in the samedirection.

6. In a multicolor sheet fed printing press, a series of at least threeprinting units each including an impression cylinder and associatedmechanism, sheet transfer means between the impression cylinders of eachpair of adjacent units, sheet grippers on said impression cylinders andon said sheet transfer means adapted to convey sheets in registerthrough the printing units, a gear train for driving said printing unitsand said sheet transfer means including a gear for each of saidimpression cylinders and sheet transfer means, two motors of unequalpower output, each of said motors being in driving relation with a gearof each of two sheet transfer means, the difference in power output ofsaid motors with relation to the load borne by each of them being suchas to cause power from the motor of greater output to be transmittedthrough the gear driven by the motor of lesser output, whereby backlashat all points in said gear train is maintained always in the samedirection.

7. In a multicolor sheet fed printing press, a series of at least threeprinting units each including an impression cylinder and associatedmechanism, a sheet transfer cylinder between each pair of adjacentimpression cylinders, sheet grippers on said impression cylinders andtransfer cylinders adapted to convey sheets in register through theprinting units, a gear for each transfer cylinder meshing with gears forthe impression cylinders on each side thereof, two driving pinions eachmeshing with a different transfer cylinder gear, two motors of unequalpower output, each motor connected to one of said driving pinions forapplying power thereto, the difference in power output of said motorsbeing such as to cause power from the motor of greater output to betransmitted through the transfer cylinder gear meshing with the piniondriven by the motor of lesser output, whereby backlash at all points inthe press between said driving pinions is maintained in the samedirection as would be the case if the press were driven only by themotor of larger output.

8. In a sheet fed rotary offset printing machine, a series of at leastthree printing units each embodying plate, blanket and impressioncylinders, transfer cylinders between the impression cylinders ofsuccessive units,

a motor of a given type and given power output operatively connectedwith one of said transfer cylinders, 21 motor of the same type andlesser power output operatively connected with another of said transfercylinders, a gear on the impression cylinder of each unit, a gear oneach transfer cylinder intermeshing with the impression cylinder gearson both sides thereof, whereby all impresison cylinders areinterconnected to turn at the same surface speed, and gear means fordriving the blanket and plate cylinders of each unit from the impressioncylinder thereof, said motors being electrically interconnected to turnat the same speed, whereby the larger motor at all speeds assumes thegreater part of the load in a fixed ratio to the load assumed by thesmaller motor.

9. In a sheet fed rotary offset printing machine, a series of at leastthree printing units each embodying plate, blanket and impressioncylinders, transfer cylinders between the impression cylinders ofsuccessive units, a motor of a given type and given power outputoperatively connected with one of said transfer cylinders, 21 motor ofthe same type and lesser power output operatively connected with anotherof said transfer cylinders, a gear on the impression cylinder of eachunit, a gear on each transfer cylinder intermeshing with the impressioncylinder gears on both sides thereof, whereby all impression cylindersare interconnected to turn at the same surface speed, a gear concentricwith and turning with each of said impression cylinders, and gears onthe plate and blanket cylinders of each unit driven by said last namedgear, said motors being electrically interconnected to turn at the samespeed, whereby the larger motor at all speeds assumes the greater partof the load in a fixed ratio to the load assumed by the smaller motor.

10. in a sheet fed rotary ofiset printing machine, a series of at leastfive printing units each embodying plate, blanket, and impressioncylinders, transfer cylinders between the impression cyiinders ofsuccessive units, a motor of a given type and given power outputoperatively connected to drive the second transfer cylinder viewed fromthe feed end of the machine, a motor of the same type and lesser poweroutput operatively connected to drive a transfer cylinder between saidlast named transfer cylinder and the transfer cylinder nearest thedelivery end of the machine, a gear on the impression cylinder of eachunit, a gear on each transfer cylinder intermeshing with the impressioncylinder gears on both sides thereof, whereby all of the impressioncylinders are interconnected to turn at the same surface speed, and gearmeans for driving the plate and blanket cylinders of each unit from theimpression cylinder thereof, said motors being electricallyinterconnected to turn at the same speed, whereby the larger motor atall speeds assumes the greater part of the load and the smaller motorcontributes driving force in a fixed ratio to that of the larger motor,strain on the gears is minimized and backlash maintained always in thesame direction.

11. In a sheet fed rotary offset printing machine, a series of at leastfour printing units each embodying plate, blanket and impressioncylinders, transfer cylinders between the impression cylinders ofsuccessive units, a motor of a given type and given power outputoperatively connected to drive the second transfer cylinder viewed fromthe feed end of the machine, a motor of the same type and lesser poweroutput operatively connected to drive the third transfer cylinder, agear on the impression cylinder of each unit, a gear on each transfercylinder intermeshing with the impression cylinder gears of the units onboth sides thereof, whereby all the impression cylinders areinterconnected to turn at the same surface speed, and gear means fordriving the blanket and plate cylinders of each unit from the impressioncylinder thereof, said motors being electrically intercom nected forspeed control, whereby the larger motor assumes the greater part of theload and the smaller motor contributes driving force in a fixed ratio tothat of the larger motor, strain on the gears is minimized and backlashmaintained always in the same direction.

12. In a sheet fed rotary offset printing press or the like, a geartrain for driving the press including a plurality of continuously meshedgears, 21 first motor operatively connected with one of the gears insaid gear train, a second motor operatively connected with another ofthe gears in said gear train, means electrically interconnecting saidmotors for turning said motors at the same speed, the load assumed byeach motor being such that the ratio of the power output of the firstsaid motor to the load on its side of the gear driven by the secondmotor being greater than ratio of the power output of the second motorto the remaining load whereby the first motor drives part of the loadlocated on the other side of the gear driven by the second motor.

References Cited in the file of this patent UNITED STATES PATENTS1,621,607 Sharpless Mar. 22, 1927 1,849,219 Belluche Mar. 15, 19322,229,973 Hormel Ian. 28, 1941 2,354,950 Feldhausen Aug. 1, 19442,484,905 Peyrebrune Oct. 18, 1949 2,549,813 Huck Apr. 24, 1951

